MUSB driver: Timeout is never detected as the while loop does not end

Timeout variable is decremented once more when while condition is not met.
Following "if" does not detect correctly that timeout has occurred.
Because of this bug the "usb start" command on AM335X-EVM board did not detect correctly that USB device was not attached.

	timeout = musb_cfg.timeout;
	while (timeout--)
		if (readb(&musbr->devctl) & MUSB_DEVCTL_HM)
 			break;
	/* if musb core is not in host mode, then return */
	if (!timeout)
		return -1;

Signed-off-by: Matej Franceskin <Matej.Franceskin@comtrade.com>
CC: Marek Vasut <matex@denx.de>?